Certified Medical Coding Specialist Case Studies & Practical Application 5 — Questions and Answers
Question 1: A patient is admitted after a motor vehicle accident and sustains a closed femur fracture and a closed tibia fracture on the same leg. The femur fracture required ORIF. Which diagnosis is sequenced first?
- The tibia fracture since it is the distal injury
- The femur fracture since it was the most serious and required surgical intervention (Correct answer)
- The external cause code for the MVA
- Either fracture, since UHDDS allows either to be principal
Correct answer: The femur fracture since it was the most serious and required surgical intervention
The condition chiefly responsible for the admission — the femur fracture requiring ORIF — is selected as the principal diagnosis.
Question 2: A physician documents 'urinary tract infection due to E. coli.' Which ICD-10-CM codes should be assigned?
- N39.0 only — the combination code includes the organism
- N39.0 and B96.20 — UTI with E. coli as the causative organism (Correct answer)
- A41.51 — sepsis due to E. coli
- B96.20 only — the organism code is sufficient
Correct answer: N39.0 and B96.20 — UTI with E. coli as the causative organism
N39.0 codes the urinary tract infection, and B96.20 (E. coli as the cause of diseases classified elsewhere) is added to identify the organism.
Question 3: A Medicare patient receives an annual wellness visit (AWV) and also has an E/M service for a new complaint addressed during the same encounter. How is this billed?
- Bill only the AWV — the E/M is bundled
- Bill only the E/M — the AWV is lesser in value
- Bill both the AWV and E/M with modifier -25 on the E/M (Correct answer)
- Bill both without any modifier since they are different service types
Correct answer: Bill both the AWV and E/M with modifier -25 on the E/M
Both can be billed on the same day with modifier -25 appended to the E/M service to indicate it was a significant, separately identifiable service.
Question 4: A patient is treated for acute osteomyelitis of the right femur caused by Staphylococcus aureus. Which code set correctly captures this?
- M86.151 and B95.8
- M86.011 and B95.61 (Correct answer)
- M86.151 and B96.20
- M86.011 and B96.89
Correct answer: M86.011 and B95.61
M86.011 covers acute hematogenous osteomyelitis of the right femur, and B95.61 identifies Staphylococcus aureus as the causative organism.
Question 5: A coder is reviewing a record where the patient was admitted for cellulitis of the left leg and also has type 1 diabetes mellitus. The physician does not document a link between the two. How should the diabetes be coded?
- E10.69 — diabetes with other specified complication
- E10.9 — type 1 diabetes without complications, as a comorbidity (Correct answer)
- E10.10 — diabetic ketoacidosis, unspecified
- Do not code the diabetes since it is unrelated
Correct answer: E10.9 — type 1 diabetes without complications, as a comorbidity
Without documentation of a link between the diabetes and the cellulitis, diabetes is coded as E10.9 (unrelated comorbidity) separately from the cellulitis.
Question 6: A physician performs an initial hospital care visit for a new patient requiring high-complexity medical decision-making. The note meets the criteria for 99223. A resident also participates and documents independently. How is teaching physician involvement handled for billing?
- Only the resident's note is used for billing
- The teaching physician must be present for key portions and document their participation for the professional fee to be billed (Correct answer)
- Both the resident and attending can each bill independently
- The teaching physician must rewrite the entire note
Correct answer: The teaching physician must be present for key portions and document their participation for the professional fee to be billed
CMS teaching physician rules require the attending to be present for the key portion of the service and document their participation in order to bill the professional fee.
Question 7: A patient is seen for low back pain and the physician orders an MRI. The MRI reveals a herniated disc at L4-L5. What diagnosis is coded for the encounter?
- Low back pain only, since the MRI result was not yet reviewed at the encounter
- The herniated disc at L4-L5 since it is the confirmed etiology of the low back pain (Correct answer)
- Both the low back pain and the herniated disc
- The MRI finding coded as an incidental finding
Correct answer: The herniated disc at L4-L5 since it is the confirmed etiology of the low back pain
Once a definitive diagnosis is established and documented, the confirmed diagnosis (herniated disc M51.16) replaces the symptom code (low back pain) per outpatient coding guidelines.
Certified Medical Coding Specialist Case Studies & Practical Application 5
A patient is admitted after a motor vehicle accident and sustains a closed femur fracture and a closed tibia fracture on the same leg.
The femur fracture required ORIF.
Which diagnosis is sequenced first?